Thanks for coming back Tom, I'll just have to try it out and see how it works out.
Tramline
Basically when mobile and not in a wireless hotspot or with a wireless internet dongle. You will see all tracks of aircraft on your screen as normal. You will not get any network traffic. For aircraft you have recorded before, you will have data in the Navdata file and photos stored on your harddrive. This will be displayed just as you have at home.
For new aircraft that you have not previously seen, the box will not be able to connect to the internet to get the details. Therefore the aircraft will show on the screen with just the mode S hex and the '...' aircraft type. It will show the same on your my log. No details for that hex will be added to your navdata.
Once you are back connected to the internet, you will be able to do a populate on the mylog to get the aircraft details/photos. You will have to manually insert the hex codes and associated data into your database explorer to populate Navdata.